Source : Webster's Revised Unabridged Dictionary (1913)

Oleoresin \O`le*o*res"in\, n. [L. oleum oil + E. resin.]
   1. (Chem.) A natural mixture of a terebinthinate oil and a
      resin.

   2. (Med.) A liquid or semiliquid preparation extracted (as
      from capsicum, cubebs, or ginger) by means of ether, and
      consisting of fixed or volatile oil holding resin in
      solution. -- {O`le*o*res"in*ous}, a.

Source : WordNet®

oleoresin
     n : a naturally occurring mixture of a resin and an essential
         oil; obtained from certain plants